Optimal Efficiency Tracking Control Scheme Based on Power Stabilization for a Wireless Power Transfer System with Multiple Receivers

Abstract

With the increase of charging requirements in electrical equipment, the wireless power transfer (WPT) system with multiple receivers has gained more attention as the charging power and efficiency of a WPT system depends on the equivalent reflected impedance of the load. Based on the circuit model analysis of a single receiver WPT system, this paper investigated the multiple-receiver WPT system. The relationship between the mutual inductance, load, and system efficiency was discussed and the optimal load, the equivalent reflected impedance, and power division method were analyzed to design the proposed system control scheme. With the use of the perturbation and observation (P&O) algorithm control method, the current of transfer and receivers were regulated to achieve stable constant power charging. Furthermore, when searching the minimum input power of the system, the optimal efficiency under a fixed power division ratio was also received. The validity of the proposed system control method was confirmed by simulation and experimental results. Under the proposed control method, an efficiency above 80% can be achieved for a multiple-receiver WPT system with a fixed power division ratio working at 6.78 MHz.

Multiple Input Multiple Output Resonant Inductive WPT Link: Optimal Terminations for Efficiency Maximization

“…, b N . In this case the power gain is G (ba) P = 1/λ, the corresponding currents are still given by u, and the solution must satisfy the constraint λ > 1 (18) which, according to ( 14), provides P a < 0 and, consequently, P b > 0. In this case the optimal gain corresponds to the minimum λ satisfying (18).…”

“…Another configuration of interest is that using a single transmitter and multiple receivers (SIMO) that allows us to recharge multiple devices by using a single transmitter [18][19][20][21][22][23].…”

Loss-Separation Strategy to Improve Efficiency of Wireless High-Power Transfer Systems in Weak-Coupling Conditions

“…Methods for optimal-load tracking the maximum energy efficiency was reported in [12], [13]. Control methods for optimal efficiency tracking was introduced in [14], [15]. Most of the published works stands on predefined topologies such as SSsystems, LCCL/S systems, doubled LCC-systems, etc., to conduct the analyses on optimizing the power efficiency via frequency selecting [7]- [9], component designs [12], [13], [16] or control approach [14], [15].…”

“…Control methods for optimal efficiency tracking was introduced in [14], [15]. Most of the published works stands on predefined topologies such as SSsystems, LCCL/S systems, doubled LCC-systems, etc., to conduct the analyses on optimizing the power efficiency via frequency selecting [7]- [9], component designs [12], [13], [16] or control approach [14], [15]. These approaches lack comparative analyses on different topologies which may lead to missed guidance on choosing appropriate topologies for practical wireless transfer applications.…”

Influence of Asymmetric Coil Parameters on the Output Power Characteristics of Wireless Power Transfer Systems and Their Applications

“…A large transmitting coil is designed to transfer power to several small receiving coils in [23], but the influence of the coupling coefficient on the system characteristics was not discussed. In [24], the problem of power allocation among multiple receivers is solved, but the effect of coupling coefficient variation is not addressed. When the coupling coefficient is relatively large, the output power of WPT system will reach its peak value at two different operating frequencies, which is known as the frequency splitting phenomenon.…”